Antonio Conte said the Video Assistant Referee system must improve after a "big mistake" in Chelsea’s FA Cup penalty shoot-out win over Norwich on Wednesday.

In an incident-packed game, there was confusion on several occasions as Chelsea had penalty appeals waved away by referee Graham Scott.

Pedro, Alvaro Morata and Willian were all booked for diving in the box and it was unclear whether Scott referred any of the decisions to the VAR.

Pedro and Morata were also sent off in extra-time, but Chelsea head coach Conte was particularly frustrated by the decision not to award a penalty for a foul on Willian.

I think that we need to improve if we want to use this new system, Conte said. Today in this game there is a very clear situation with Willian. I think the situation was very clear and I watched and it’s a penalty, very clear.

The referee quickly took a decision to book Willian. It means you don’t have doubt…if we want to improve this new system you have to wait to check with the person that is watching the game and then if this person is sure, 100 per cent, then OK it’s simulation book him.

The person that is watching the game must have a doubt because there is a kick to Willian, and in this case you have to call the referee and tell him there is a doubt, maybe it’s not a penalty, but it’s better if you go watch the decision.

The Willian penalty was a big mistake. Not for the referee on the pitch, but the person watching the game, if you are watching and don’t see that situation…he must improve.

To avoid a big mistake you have to call the referee and tell him: ‘maybe this situation, there is a doubt, for me it’s no penalty but it’s better you go watch and then make the decision’. We have to respect the referee on the pitch and he has to make the final decision, not another person saying they are 100 per cent sure and don’t call the referee. The referee watches and then makes the best decision.

You must be sure 100 per cent. There is another person checking and if they call and say it’s a penalty you give a penalty and say it’s a mistake and no yellow card. We have to find the solution.

Norwich boss Daniel Farke had said before the game that he was unconvinced by VAR after seeing it used in his native Germany.

And, speaking after the defeat to Chelsea, he said: There are some problems in Germany. I am a bit old fashioned and not a deep believer in changing the game too much because I like the traditional game, but we have to be open in improvement if technology can improve the quality of the decisions.

There are several examples like goal-line technology which helps, but it’s really difficult and you have to have solutions in a fluid game like football. We have some problems in Germany and some big discussions.

It’s a good idea but it’s a bit tricky to handle and we have to find a good way to handle it, but it doesn’t work from the start and perhaps it needs some time and we will see how it develops.

(c) Sky News 2018: Chelsea boss Antonio Conte says VAR system must improve after ‘big mistake’